It is well known to collect blood from donors in pre-assembled and pre-sterilized blood collection systems. Such systems typically include a primary collection container and at least several separate satellite containers interconnected with associated flexible tubing, flow control devices and filters, as desired. Such systems may also include blood cell preservatives and other solutions. Typically, whole blood is drawn into the primary collection container through a vascular access needle. After collection, the entire system, including primary container, satellite containers, fluid flow tubing, flow control devices and filters, is placed into a centrifuge and the entire assembly is subject to centrifugation. During centrifugation, the blood in the primary collection container separates by reason of the different density of the blood components, into more dense concentrated red blood cells at one end of the container and lighter plasma toward the other end of the container, with an intermediate layer, sometimes referred to as buffy coat, which may comprise leukocytes and platelets.
Following centrifugation, the plasma is expressed through flow tubing and into a plasma collection or first satellite container. Also, a leukocyte reduction filter may be provided in the fluid flow tubing so that any leukocyte population in the plasma is reduced as the plasma is expressed into the plasma collection container. The plasma collection container may then be sealed and severed from the remainder of the system for subsequent administration to patients or later processing as a fresh frozen plasma. If the centrifugation is carried out at sufficiently low speeds or time so as to allow substantial numbers of platelets to remain in the plasma, the collected plasma may be subject to further centrifugation for separation into platelet-poor or platelet-depleted plasma and platelet concentrate. During such centrifugation, the platelet-poor plasma accumulates toward one end of the plasma collection container and the platelet concentrate collects toward the other end of the plasma collection container. The platelet-poor plasma may then be expressed from the first satellite container into a second satellite container for storage, administration to patients or subsequent processing. A platelet preservative may be added to the platelet concentrate remaining in the first satellite container to enhance viability during storage. The remaining red blood cell concentrate in the primary container may be stored there or be expressed into other satellite containers and combined with a red cell preservative solution to extend the storage life of the red cells.
If the centrifugation of the primary container is at sufficiently high speed or for sufficiently long time, platelets may be forced into the intermediate cell layer (buffy coat). In that situation, typically the plasma will be expressed from the primary container leaving the buffy coat and red cells in the container. The red cells may be expressed from the primary container, allowing the buffy coat layer to remain therein, or the remaining contents may be agitated to mix the platelets and leukocytes with the red cells, which may remain in the primary container or be expressed to another container.
Although blood collection systems such as that described above offer significant advantages in terms of user convenience, the manufacturer of such systems can be relatively complex and the systems can be relatively expensive. This can present a drawback in the event the system must be discarded before it is fully utilized. For example, it may be determined after collection that a particular donor was not qualified to provide a blood donation, in which the event the entire blood component collection system with all the associated containers, flow control devices and filters will need to be discarded.
It has been suggested to address these issues by collecting blood from a donor into a system having a single container, leaving subsequent processing in the hands of other trained personnel associated with the blood bank or collection agency, who can manipulate and process the collected blood in a manner desired at that time. (U.S. Pat. No. 6,994,790). Although, this approach may be useful in certain circumstances, there continues to be a need for new systems, apparatus and methods that advance the efficiency of blood collection and processing and provide other benefits.
Such advances are provided in significant part by the subject matter of this description and the associated drawings accompanying it.